Does abnormal uterine development affect pregnancy?

Cases of uterine dysplasia are often heard. When hearing about the disease, many women worry that their fertility will be affected and they will not be able to complete their life plan of having children. Professional obstetricians and gynecologists say that uterine dysplasia is a type of reproductive organ malformation. Although it may affect fertility, it does not mean that pregnancy is completely impossible. As long as appropriate surgery and treatment are combined, there is still a high chance of successful pregnancy.

Case Study

Jiayu and her husband have been married for five years. The couple has always hoped to have a cute baby soon. However, they have tried several pregnancy plans but still have no sign of pregnancy. So Jiayu decided to go to the obstetrics and gynecology department. After ultrasound and fallopian tube photography, the doctor diagnosed Jiayu as a patient with "septate uterus".

A brief discussion on embryonic development

Cathay General Hospital obstetrics and gynecology attending physician Lin Meiyi said that the development of embryonic gonads begins around the 5th to 6th week of pregnancy. Before the 9th week of pregnancy, there is no difference in morphology between male and female embryos. The Wolffianduct and Mullerianduct exist at the same time, and the external genitalia are not differentiated. After that, the two sexes begin to move in different directions under the guidance of different genes. For females, the Wolffianduct will degenerate, and the Mullerianducts on both sides will symmetrically extend to the midline and heal and differentiate into the fallopian tubes, uterus and part of the vagina; the probability and type of congenital uterine abnormalities vary depending on the differentiation of the Mullerian ducts.

Mullerian ducts are not developed on both sides

Congenital absence of uterus is also known as Mayer-Rokitansky-Kuster-Hausersyndrome. The probability is about 1 in 5,000 to 20,000. The cause is that after the two sides of the Mullerian ducts heal in the midline, they stop developing downwards, resulting in a situation where there is no uterus and partial or complete absence of vagina. This type of patient has normal ovaries and secondary sexual characteristics, which are usually discovered when menstruation does not occur during puberty. Since there is no vagina at all or only a partial vagina (the lower 1/3 of the normal vagina), vaginal dilation or artificial vaginal surgery is often required to perform sexual intercourse. Because of congenital absence of uterus, if you want to get pregnant, you must rely on a surrogate mother, but current Taiwanese law does not allow this practice.

Only one side of the Müllerian duct is well developed

Unicornuate uterus

If only one side of the Mullerian duct develops, the reproductive prognosis is poor, and some patients even have only one ovary and fallopian tube. There is a possibility of miscarriage, premature birth, or intrauterine growth retardation and malposition of the fetus, and it is often accompanied by unilateral renal failure.

Remnant uterine horn

Only one side of the Mullerian duct is well developed, while the other side is poorly developed. The poorly developed side will form a residual uterine horn. If it is not connected to the other side, symptoms of menstrual blood retention such as periodic lower abdominal pain may occur after puberty; if it is connected to the other side, pregnancy is possible, but a residual uterine horn pregnancy will occur (similar to an ectopic pregnancy, and there is a possibility of heavy bleeding). In addition, Lin Meiyi

Doctors point out that this type of patient often has abnormalities in the ipsilateral kidney.

Blind angle uterus

The blind horn uterus is a condition where the Mullerian ducts on both sides are well developed, but one side does not open in the vagina, resulting in a blocked uterine horn. After puberty, when menstruation comes, menstrual blood retention often causes periodic lower abdominal pain, which may cause hematochezia and hematosalpinx. Menstrual blood may even flow into the abdominal cavity through the opening of the fallopian tube fimbria. Patients often have urinary system abnormalities. Dr. Lin Meiyi said that patients can feel a growing mass in the lower abdomen. The treatment method is to remove the septum between the blind horn uterus and the opposite uterine cavity or vaginal cavity to allow the menstrual blood to flow out.

The Mullerian ducts on both sides are well developed, but there is a problem with fusion

Double uterus

The Mullerian ducts on both sides are well developed but not completely fused. The patient will have a double uterus, double cervix, and some will have a single or double vagina. Generally speaking, patients with a double uterus have good fertility, but patients with double vaginas or vaginal septums often have difficulty in sexual intercourse and it is more difficult to give birth from the vagina. When the patient has a history of pelvic pain, recurrent miscarriage, or premature birth, hysteroplasty can be considered. Dr. Lin Meiyi explained: "In theory, a double uterus does not cause infertility. If a patient has a double uterus and infertility at the same time, the cause of infertility should be carefully explored and treated to treat the symptoms and the root cause." In addition, some patients with a double uterus may have unilateral (especially right) vaginal obstruction or kidney abnormalities, so more attention should be paid.

Bicornuate uterus

The Mullerian ducts on both sides are well developed but not completely fused, resulting in incomplete fusion of the uterine fundus, causing one corner of the uterus to protrude on each side, which is a bicornuate uterus. Depending on the degree of inward concavity of the uterine fundus, the so-called "saddle-shaped uterus", "heart-shaped uterus", and "arcuate uterus" will be formed, which may cause miscarriage or abnormal fetal position during pregnancy.

Septum uterus

The Mullerian ducts on both sides are well developed. When they fuse, only a septum remains in the middle of the uterus, but the uterus has a normal appearance. The longer the remaining septum is, the higher the chance of recurrent miscarriage and premature birth. However, this is not an absolute result. Most untreated patients do not have problems with pregnancy and childbirth. If treatment is required, the septum can be removed by hysteroscopy. Dr. Lin Meiyi explained that according to statistics, among cases of abnormal uterine structure, the proportion of uterus with septate uterus accounts for the largest proportion, followed by bicornuate uterus, unicornuate uterus, and didelphys. The least common case is congenital absence of uterus.

How to diagnose

Most patients with congenital uterine anomalies do not have any symptoms, and many people will never find out about it in their lifetime. Many of them discover the condition by chance through ultrasound, and some people discover it during infertility examinations. Statistically, about 2% to 4% of women of childbearing age have congenital uterine anomalies, and about 5% to 10% of infertile patients have congenital uterine anomalies.

Dr. Lin Meiyi said that if you find yourself having problems such as habitual miscarriage or infertility, it is best to see a doctor during the golden period for a check-up. It is usually not difficult to detect the problem. If it cannot be clearly identified through ultrasound, the doctor will also use fallopian tube photography, laparoscopy or magnetic resonance imaging to obtain the most accurate results.

Doctor's kind advice

Dr. Lin Meiyi said that under natural conditions, patients with abnormal uterine structure are indeed more likely to have problems such as difficulty in pregnancy and infertility (among which patients with congenital absence of uterus may not even be able to get pregnant at all), but if they undergo IVF, the chance of pregnancy will be the same as that of ordinary people, and will not be particularly low. Although patients with congenital uterine abnormalities are more likely to have some obstetric complications than ordinary people once they become pregnant, such as recurrent miscarriages, premature births, intrauterine growth retardation, antenatal and postpartum hemorrhage, incomplete cervical occlusion, malposition of the fetus, and cesarean section rates, if patients can cooperate well with obstetricians, they can still give birth to a healthy next generation. In addition, women with abnormal uterine structure often have urinary tract abnormalities, so kidney and ureteral photography should be performed at the same time as the diagnosis, so that early treatment and correction can be carried out as soon as possible.